The present invention relates generally to wireless communication systems and, in particular, to selectively communicating in a wireless communication system based on varying time incremental costs of communication.
Wireless communication systems are known to include a system infrastructure and a plurality of communication devices. Such systems include, but are not limited to, cellular systems, trunked land mobile systems, paging systems, personal communication systems, wireless local loops, wireless data systems, and satellite-based systems. For example, a cellular communication system includes cellular infrastructure (e.g., base sites, base site controllers, mobile switching centers, and home location registers) and radiotelephones. Similarly, a paging communication system includes paging infrastructure (e.g., base sites and central controllers) and one-way or two-way pagers.
To obtain service from a wireless communication system, a user must first request service from the system operator. This request typically involves visiting the system operator or one of its authorized dealers, determining which service plan is most cost-effective based on estimated system usage, and executing a service contract directed to the selected plan. The operator or its dealer also informs the user of the time incremental costs, if any, for using the system in excess of the time allotted in the plan. Such time incremental costs are typically referred to as prime and non-prime rates. The prime and non-prime rates are fixed for certain time periods during the day and days during the week. The non-prime rate is less than the prime rate in an attempt to encourage users to call during non-peak periods (e.g., between 9:00 PM and 6:00 AM Monday-Friday and all day Saturday and Sunday).
However, such simple assignment of prime and non-prime rates does not account for current system traffic on any particular day or at any particular time. For example, if traffic is unusually low during the peak period on Columbus Day (a Monday) at a base site heavily used by government employees because such government employees are off of work, other users are not likely to increase their usage because they must pay the prime rate. Consequently, the system operator""s income for that particular day is reduced due to the low peak period traffic. Therefore, although fixed assignment of time incremental costs may be adequate, it is clearly not optimal since system traffic can vary for many reasons.
To anticipate reduced traffic periods and attempt to increase traffic during those periods, system operators advertise reduce rates during the periods (e.g., on holidays). However, these attempts at increasing traffic require advance notice by print mail, by public radio advertising, or by leaving a voice mail in the voice mailbox of system users that receive voice mail service. Therefore, although advanced advertising may help increase traffic on days in which lower traffic can be anticipated, such advertising does nothing for unanticipated periods of reduced traffic.
Although most systems do not provide cost information to users other than in a fixed manner at the user""s sign-up of service or at other fixed intervals (e.g., in a print mailing), some systems do provide current costs to the user or the user""s communication device. However, these systems use the costs either to simply inform the user how much the ongoing communication is costing the user or to load the current costs in the communication device for charging the user for his or her ongoing communication. For example, U.S. Pat. No. 3,769,463 discloses a device for displaying the current cost of a long distance call to a user of a standard telephone. The device automatically responds to the user""s initiation of a call and displays the elapsed time and cost of the call. However, the device does not inform the user, prior to initiation of the call, of the current time, incremental costs associated with using the telephone system as such costs may be varied by the telephone system operator.
As another example, U.S. Pat. No. 5,848,138 discloses a method for transmitting tariff data to a subscriber unit. As described in this patent, the system infrastructure of a wireless"" local loop transmits the appropriate tariff data to the chargeable subscriber unit (i.e., pay phone) currently being used by the user to insure that the user is being fairly charged for a call. That is, the chargeable subscriber unit receives tariff data at the beginning of a call made from the pay phone (i.e., after the user has initiated the call) and at appropriate times during the call coinciding with the times at which additional costs are due. For example, after the user lifts the pay phone receiver and dials a telephone number (i.e., initiates a call), the system infrastructure transmits tariff data to the pay phone (e.g., $0.50 for the first three minutes). During the user""s use of the phone, the phone receives charge-metering pulses from the system infrastructure to track the current cost of the call. When the number of pulses exceeds the number associated with the transmitted tariff data (i.e., when the call has exceeded the original 50 cent cost), the system infrastructure transmits new tariff data to the pay phone (e.g., $0.30 for the next three minutes). In this way, if the tariff changed during the call, the user is charged the correct amounts. Although this patent may enable system users to be charged more fairly, it does not enable users to regularly determine the time incremental costs of future communications so that the users can determine whether the importance of their calls is worth the potential cost. In addition, the patent does not provide a means for system operators to influence system load over time by varying tariff rates and informing system users of the varying rates.
Therefore, a need exists for a method and apparatus for selectively communicating in a wireless communication system that informs system users in real-time of varying communication rates, thereby enabling users to perform cost-benefit analyses immediately before initiating their communications and enabling system operators to attempt to balance system load during the actual time periods of system imbalance. Such a method and apparatus that also facilitates negotiation of communication costs on a communication unit-by-communication unit basis would be a further improvement over the prior art.